Leave the wood at home

Invasive tree killing species of insects might travel as many as 40 miles a year by natural migration but by hitching a ride with campers, they can travel across the continent in a single year.

Many campers bring firewood with them when they camp. The U.S. Forest Service and state forestry agencies around the country say transporting firewood lets tree-killing insects hitch a ride into the woods, contributing to billions of dollars in damage and needless work each year.

Officials advise campers to get firewood at or near their destinations instead.

Most invasive insect species are introduced to North America from Asia and Europe via international trade. The invaders often have no local predators, allowing them to flourish unchecked.

The most damaging of the current infestations is from the emerald ash borer, an insect that has infested about 40,000 square miles in Michigan, Indiana, Ohio, Maryland and Ontario Province and killed more than 20 million ash trees.

The borer is a metallic-green beetle about a half-inch long. Its larvae feed on the layer of wood just beneath the bark, cutting off water and nutrients. If allowed to spread unchecked, the beetle could do to the ash population what Dutch elm disease has done to the elm population.